Anson Resources has dramatically expanded its Green River Lithium Project resource estimate by 650%, driven by new drilling data and expanded claim areas in Utah. The upgrade positions the project closer to a milestone of over one million tonnes of lithium carbonate equivalent.
- JORC Resource estimate increased by 650%
- Indicated Resource up 863% to 183,000 tonnes LCE
- Inferred Resource up 602% to 590,000 tonnes LCE
- Resource confined to Mississippian Leadville Limestone aquifer
- Additional mineral rights applications underway
Massive Resource Upgrade at Green River
Anson Resources (ASX:ASN) has announced a seismic 650% upgrade to the JORC Mineral Resource estimate for its Green River Lithium Project in southeastern Utah. The Indicated Resource surged by 863% to 183,000 tonnes of lithium carbonate equivalent (LCE), while the Inferred Resource climbed 602% to 590,000 tonnes LCE. This leap is anchored in new drilling results from the Bosydaba #1 and Mt Fuel-Skyline Geyser 1-25 wells, coupled with an expanded claim footprint that the company expects to further enlarge through pending mineral rights applications.
Geological Confidence and Resource Boundaries
The resource upgrade is based solely on the Mississippian Leadville Limestone aquifer, a stratigraphic unit uniformly present beneath the project area. Extensive 3D geological modelling, developed using data from 282 historical wells within a 25 km radius and the company’s own drilling, underpins the resource boundaries. The Indicated Resource area extends in a 20.52 km2 radius around the Bosydaba #1 well, reflecting higher confidence in stratigraphy and lithium grades. The broader Inferred Resource covers 69.80 km2, including the Mt Fuel-Skyline Geyser well area.
Average porosity is conservatively set at 6%, with 100% brine saturation assumed in the pore spaces. This yields brine volumes of 0.269 km3 (Indicated) and 0.868 km3 (Inferred). Lithium concentrations average 127.8 mg/L based on 2025–2026 assay results, a notable increase from 2024 samples, possibly reflecting aquifer geochemical equilibration over time.
Drilling Fluid Assays Support Higher Grades
Technical challenges during drilling at Mt Fuel-Skyline Geyser 1-25 prevented direct brine sampling, but assays of recovered drilling fluids revealed lithium grades up to 148 ppm. These results align with expectations of higher grades near geological fault lines and corroborate earlier assays from Bosydaba #1. The consistency between drilling fluid and brine assays lends credibility to the resource upgrade and supports the company’s stratigraphic and geochemical model.
This development follows earlier reports of lithium grades up to 148ppm, which helped underpin the resource revision.
Direct Lithium Extraction Technology Progress
Anson is advancing Direct Lithium Extraction (DLE) technology to unlock the lithium from hypersaline brines sustainably. The company has partnered with Koch Technology Solutions and POSCO Holdings to operate a pilot DLE demonstration plant adjacent to the Bosydaba #1 well. Recent test work has produced lithium carbonate eluate at 99.4% purity, meeting battery-grade standards. The high-pressure, high-temperature conditions confirmed by Drill Stem Tests across the project area inform the design of the processing plant and indicate favorable extraction parameters.
This technological progress is part of Anson’s broader strategy to develop a commercially viable lithium operation, building on the project's geological potential and existing infrastructure. The company has recently submitted a final major permit submission for a 10,000 tpa lithium carbonate plant, marking a significant step towards production.
Resource Expansion Potential and Next Steps
Anson is actively pursuing additional mineral rights within an expanded Area of Interest, which could further increase the resource base without the need for immediate additional drilling. The company’s Executive Chairman Bruce Richardson highlighted the team's efforts over the past year in expanding land holdings, drilling, and developing a detailed geological and hydrogeological model. Achieving over one million tonnes of LCE in combined Indicated and Inferred Resources appears within reach.
However, the resource remains at an early stage, with a significant portion classified as Inferred and no demonstrated economic viability yet. The variability in lithium concentrations over time and the evolving nature of DLE technology introduce uncertainties that require ongoing technical validation. Further sampling, pilot plant results, and regulatory approvals will be critical milestones to watch.
Recent advances in porosity assessment and hydrogeological understanding are also shaping the project’s outlook, as highlighted in the company’s recent higher porosity report.
Bottom Line?
Anson’s Green River upgrade marks a leap forward, but the path to commercial lithium production hinges on proving consistent lithium grades across the property and scaling DLE technology effectively.
Questions in the middle?
- Will additional mineral rights applications deliver the anticipated resource growth without further drilling?
- How will lithium concentration variability impact long-term extraction economics and resource classification?
- Can the DLE pilot plant scale successfully to commercial production with consistent lithium recovery?